pump question? 3

[banshee33]

hello , new to forum , not an engineer , just a wrench puller .i would like some one to explain something to me about a single stage ansi pump . if i have to pumps in parallel , only using one pump at a time . both pumps identical , suction size,discharge size, same impeller size . one pump has a electric motor with a 200 hp rating and the other has an electric motor with a 400 hp rating , both motors run the same rpm . what happens to the flow or head between the two ? only running one pump at a time .

 

[zdas04]

When I've seen industrial power bills, they have based the demand charge on the magnitude of the start-up spike. The better job you do of soft-starting, the lower the demand charge.

David

 

[BigInch]

77JQX
Most of the motor to load efficiency curves I've seen are more or less flat to 50-60% load and head downhill fast from there. I idealized the curves to a straight line from 0,0 to 75% eff at 50% load, 90% eff at 60% load to 94% eff for a new hi eff motor at full load. And you might also get 105% efficency at 110% load ... believe it or not.

bimr, david.. Thx

Only put off until tomorrow what you are willing to die having left undone. - Pablo Picasso